Fix for question ID

user can add question from existing file
Merge remote-tracking branch 'origin/master'

Conflicts:
	ExamMaker.v12.suo
	ExamMaker/MainWindow.xaml.cs
	ExamMaker/bin/Debug/ExamMaker.exe
	ExamMaker/bin/Debug/ExamMaker.pdb
	ExamMaker/obj/Debug/ExamMaker.exe
	ExamMaker/obj/Debug/ExamMaker.pdb
	ExamMaker/obj/Debug/ExamMaker_MarkupCompile.i.cache